Institutional Ownership
Spero Therapeutics Inc
CUSIP 84833T103COMSPROQ1 2026
13D / 13G Filings
31
Schedule 13D/13G on record
Beneficial Filers
11
Distinct reporting persons
Largest Stake
20.0%
Max % of class reported
Institutional Holders
47
13F filers (latest quarter)
Beneficial Owners — Schedule 13D / 13G
31 filings · latest Aug 14, 2025
| # | Filed | Reporting Person | Form | % of Class | Shares | Filing |
|---|---|---|---|---|---|---|
| 1 | Aug 14, 2025 | Anson Funds Management LP | 13G/A | 2.9% | 1.62M | SEC |
| 2 | Mar 28, 2025 | Gsk PLC | 13D/A | 16.4% | — | SEC |
| 3 | Nov 14, 2024 | Anson Funds Management LP | 13G/A | 6.9% | 3.75M | SEC |
| 4 | Feb 14, 2024 | Anson Funds Management LP | 13G | 8.1% | 4.30M | SEC |
| 5 | Feb 14, 2023 | Aquilo Capital Management, LLC | 13G/A | — | — | SEC |
| 6 | Feb 14, 2023 | Biotechnology Value Fund L P | 13G/A | — | — | SEC |
| 7 | Jan 20, 2023 | Gsk PLC | 13D/A | 17.8% | 9.19M | SEC |
| 8 | Nov 14, 2022 | Gsk PLC | 13D/A | 20.0% | 9.19M | SEC |
| 9 | Oct 3, 2022 | Aquilo Capital Management, LLC | 13G/A | 3.6% | 1.24M | SEC |
| 10 | Jul 8, 2022 | Blackrock Inc. | 13G | 2.1% | 690.8K | SEC |
21 more beneficial-ownership filings on Premium
See the full Schedule 13D/13G history for Spero Therapeutics Inc.
Unlock full historyTop Institutional Holders (13F)
Largest reported positions · latest quarter
| # | Fund | Shares | Value |
|---|---|---|---|
| 1 | Gsk PLC | 9.19M | $21.51M |
| 2 | Pfizer Inc | 2.36M | $5.50M |
| 3 | Renaissance Technologies LLC | 1.19M | $2.78M |
| 4 | Alphabet Inc. | 890.0K | $2.08M |
| 5 | Two Sigma Investments, LP | 885.6K | $2.07M |
| 6 | Geode Capital Management, LLC | 519.9K | $1.22M |
| 7 | Blackrock, Inc. | 433.2K | $1.01M |
| 8 | Anson Funds Management LP | 422.0K | $987.4K |
| 9 | Citadel Advisors LLC | 376.5K | $880.9K |
| 10 | Susquehanna International Group, LLP | 333.1K | $779.5K |